44© POPULAR SCIENCE MONTHLY. 



vegetable matter proceeds with far greater rapidity during the sum- 

 mer quarter than during other months of the year. Among the 

 early results of summer heat is the damage to food. Milk retailed 

 through the city, the sole or chief diet of thousands of hand-fed 

 infants, undergoes such changes as to render it not only less nutri- 

 tious but also hurtful to the digestive organs. The vegetables and 

 fruits in the markets rapidly deteriorate and become unfit for food. 

 Meats and fish quickly take on putrefactive changes which render 

 them more or less indigestible. The effect of this increase of tem- 

 perature upon the refuse and filth of the streets, courts, and alleys, 

 upon the air in close places, in the tenement houses, and upon the 

 tenants themselves is soon perceptible. The foul gases of decomposi- 

 tion fill the atmosphere of the city and render the air of close and 

 unventilated places stifling; while languor, depression, and debility 

 fall upon the population like a widespread epidemic. The physician 

 now recognizes the fact that a new element has entered into the 

 medical constitution of the season. The sickly young, the enfeebled 

 old, those exhausted from wasting diseases, whose native energies 

 were just sufficient to maintain their tenure of life, are the first to 

 succumb to this pressure upon their vital resources. Diarrhceal dis- 

 eases of every form next appear and assume a fatal intensity, and 

 finally the occurrence of sunstroke (or heat-stroke) determines the 

 maximum effects of heat upon the public health. The sickness rec- 

 ords of dispensaries and the mortality records of the Health Depart- 

 ment show that a new and most destructive force is now operating, 

 not only in the diseases above mentioned, but in nearly all of the dis- 

 eases of the period. Fevers, inflammatory diseases, and others of a 

 similar nature run a more rapid course, and are far less amenable to 

 treatment. This is due, in the opinion of eminent medical authority, 

 to the addition of the heat of the air to the heat of the body. Indeed, 

 the only safety is in flight from the city to the country and to cool 

 localities, as the seashore or the mountains. The immediate im- 

 provement of those suffering from affections of the city when trans- 

 ferred to the country is often marvelous, and shows conclusively 

 how fatal is the element of heat in its direct and indirect effects upon 

 the residents of the city. 



Let us next consider the causes of high temperature in the city 

 of Xew York. It is a well-established fact that the temperature of 

 large and densely populated towns is far higher than the surround- 

 ing country. This is due to a variety of causes, the chief of which 

 are the absence of vegetation ; the drainage and hence the dryness of 

 the soil; the covering of the earth with stone, bricks, and mortar; 

 the aggregation of population to surface area; the massing together 

 of buildings ; and the artificial heat of workshops and manufactories. 



